1. Field of the Invention
The present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition, and an actinic ray-sensitive or radiation-sensitive film and a pattern forming method each using the same. More specifically, the present invention relates to an actinic ray-sensitive or radiation-sensitive resin composition suitably used for the ultramicrolithography process applicable to the production process of VLSI and a high-capacity microchip, the preparation process of a nanoimprint mold, the production process of a high-density information recording medium, and the like, and for other photofabrication processes, and an actinic ray-sensitive or radiation-sensitive film and a pattern forming method each using the same. In particular, the invention relates to an actinic ray-sensitive or radiation-sensitive resin composition suitable for exposure by an immersion projection exposure apparatus with far ultraviolet rays of the wavelength of 300 nm or less as a light source, and an actinic ray-sensitive or radiation-sensitive film and a pattern forming method each using the same.
As used herein, the term “actinic ray” or “radiation” refers to, for example, a bright line spectrum of a mercury lamp, far ultraviolet rays typified by an excimer laser, extreme-ultraviolet (EUV) rays, X-rays or an electron beam (EB). Also, the term “light” as used herein means actinic rays or radiation.
Unless otherwise specifically indicated, the term “exposure” as used herein includes not only irradiation of light by a mercury lamp, far ultraviolet rays, X-rays, EUV light or the like but also lithography with a particle beam such as electron beam or ion beam.
2. Description of the Related Art
A chemical amplification type resist composition is a pattern formation material which is capable of forming a pattern on a substrate by generating an acid in the exposed area upon irradiation of radiation, for example, far ultraviolet rays, and making a difference in the solubility in a developer between the unirradiated area and the irradiated area, through a reaction using the generated acid as a catalyst.
When a KrF excimer laser is used as a light source for exposure, the chemical amplification type resist composition is mainly composed of a resist resin having as a basic skeleton, poly(hydroxystyrene) that has a weak absorption in a wavelength region of 248 nm. Therefore, such a composition is a favorable system capable of forming a good-quality pattern with high sensitivity and high resolution, as compared to the conventional naphthoquinone-diazide/novolak resin system.
On the other hand, when a light source having a shorter wavelength, for example, an ArF excimer laser (193 nm) is used for exposure, the chemical amplification type resist composition mentioned above is not satisfactory since an aromatic group-containing compound used in the composition intrinsically shows strong absorption at a wavelength region of 193 nm.
In order to address such a problem, through replacement with a resin having poly(hydroxystyrene) as a basic skeleton, a resist composition for use with an ArF excimer laser, containing a resin having an alicyclic hydrocarbon structure as a main component, has been developed. For example, there is a resist composition using an acid-decomposable resin formed by copolymerization of hydrophilic units containing an ether bond as an acid-decomposable group (for example, WO2007/094473A and JP2010-102033A).
However, it is extremely difficult to find an appropriate combination of a resin, an acid generator, an additive, a solvent and the like to be employed, from the viewpoint of overall performance of the resist, and these resist compositions have problems to be solved in terms of improving a roughness property and inhibiting pattern collapse.